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650 MHz Cryomodule Design, 21 Feb 2011 Page 1650 MHz Cryomodule Design, 21 Feb 2011 Page 1Page 1
Project X Cryomodules
Tom Peterson and Yuriy Orlov
with material from our SRF cavity and cryomodule design team
21 February 2011
650 MHz Cryomodule Design, 21 Feb 2011 Page 2650 MHz Cryomodule Design, 21 Feb 2011 Page 2
Project X Reference Design
Cryomodules for CW linac
Page 3
SRF LinacTechnology Map
=0.11 =0.22 =0.4 =0.61 =0.9
325 MHz2.5-160 MeV
=1.0
1.3 GHz3-8 GeV
650 MHz0.16-3 GeV
Section Freq Energy (MeV) Cav/mag/CM Type
SSR0 (G=0.11) 325 2.5-10 18 /18/1 SSR, solenoid
SSR1 (G=0.22) 325 10-42 20/20/ 2 SSR, solenoid
SSR2 (G=0.4) 325 42-160 40/20/4 SSR, solenoid
LB 650 (G=0.61) 650 160-460 36 /24/6 5-cell elliptical, doublet
HB 650 (G=0.9) 650 460-3000 160/40/20 5-cell elliptical, doublet
ILC 1.3 (G=1.0) 1300 3000-8000 224 /28 /28 9-cell elliptical, quad
CW Pulsed
InPAC 2011 – J. Kerby Page 3
650 MHz Cryomodule Design, 21 Feb 2011 Page 4650 MHz Cryomodule Design, 21 Feb 2011 Page 4
Design team
• 650 MHz cryomodules – Camille Ginsburg, Yuriy Orlov, and Prashant Khare
are leading and organizing the effort with me
• Cavities, input couplers, magnets, magnet current leads, tuners, instrumentation, 325 MHz cryomodules, microphonics, etc. – Many other people within Fermilab and within the
Project X collaboration
650 MHz Cryomodule Design, 21 Feb 2011 Page 5650 MHz Cryomodule Design, 21 Feb 2011 Page 5
Approach
• CW cryomodules with as much as 25 W per cavity at 2 K and tight constraints on cavity frequency present some different problems from TESLA/ILC cryomodules – Over 200 W at 2 K per cryomodule as opposed to
about 12 W at 2 K per cryomodule
• Let’s look at the requirements, consider what other labs have already done, and select best features for our own design
650 MHz Cryomodule Design, 21 Feb 2011 Page 6650 MHz Cryomodule Design, 21 Feb 2011 Page 6
Our plan
• Analyses, modeling, and reviews of various concepts based on existing designs
• Following visits to HZB, DESY, and TTC meeting (Feb 21 - Mar 3), down-select a more specific design approach – Goal is to have a specific 650 MHz cryomodule
design proposal for discussion before the Project X Collaboration meeting (April 11)
– Also complete (draft) specifications and fundamental CM parameter lists in this timeframe
650 MHz Cryomodule Design, 21 Feb 2011 Page 7650 MHz Cryomodule Design, 21 Feb 2011 Page 7
General arrangements under consideration
• Segmentation level and cavity support structure – String: BESSY/HZB (and Cornell ERL) liquid managed
separately for each CM, 2-phase pipe closed at each end, but otherwise a string, TESLA style piping and supports
– Stand-alone: three options for configuration at the individual cryomodule level
• Completely close a TESLA style CM at each end • Eliminate 300 mm pipe -- space frame support• Eliminate 300 mm pipe -- support posts and frame (325 MHz
concept from Tom Nicol)
• Helium vessel – Closed, TESLA-style, 2-phase pipe connected to helium vessel – Open, Jlab/SNS style, 2-phase flow through helium vessel
650 MHz Cryomodule Design, 21 Feb 2011 Page 8650 MHz Cryomodule Design, 21 Feb 2011 Page 8
Cryomodule style
• Very high heat flux (200 W per CM) and relatively short linac (not large quantity production nor several km long strings) ==> – Need separated liquid management – Prefer small heat exchangers, distributed with cryomodules – Prefer stand-alone cryomodules, warm magnets and
instrumentation between cryomodules like at SNS
• Stand-alone CM ==> – “300 mm” pipe is unnecessary for helium flow
• Not need 300 mm pipe for helium flow ==> – Empty 300 mm pipe as support ‘backbone” or – Different support structure (space frame or posts)
650 MHz Cryomodule Design, 21 Feb 2011 Page 9650 MHz Cryomodule Design, 21 Feb 2011 Page 9
Helium vessel style
• Helium vessel style (open vs. closed) is independent of support style (hung from 300 mm pipe or not)
• High heat loads and tight pressure stability ==> – Large liquid-vapor surface area for liquid-vapor equilibrium – Acts as thermal/pressure buffer with heat and pressure changes
• Linac is short enough that total helium inventory not an issue ==> – Open helium vessel is feasible
• For the stand-alone CW cryomodule, a closed TESLA-type helium vessel may be favored by – Tuner design – Input coupler design – And allowed by reduced pressure sensitivity
650 MHz Cryomodule Design, 21 Feb 2011 Page 10650 MHz Cryomodule Design, 21 Feb 2011 Page 10
SNS vs TTF cryomodule
TTF: vacuum vessel string. End boxes and bellows would become part of vacuum/pressure closure
SNS (like CEBAF): self-contained vacuum vessel “stand-alone” style
650 MHz Cryomodule Design, 21 Feb 2011 Page 11650 MHz Cryomodule Design, 21 Feb 2011 Page 11
Cryomodule requirements -- major components
• Eight (8) dressed RF cavities • Eight RF power input couplers • One intermediate temperature thermal shield • Cryogenic valves
– 2.0 K liquid level control valve – Cool-down/warm-up valve – 5 K thermal intercept flow control valve
• Pipe and cavity support structure • Instrumentation -- RF, pressure, temperature, etc. • Heat exchanger for 4.5 K to 2.2 K precooling of the liquid
supply flow • Bayonet connections for helium supply and return
650 MHz Cryomodule Design, 21 Feb 2011 Page 12650 MHz Cryomodule Design, 21 Feb 2011 Page 12
Cryomodule requirements -- major interfaces
• Bayonet connections for helium supply and return • Vacuum vessel support structure • Beam tube connections at the cryomodule ends • RF waveguide to input couplers • Instrumentation connectors on the vacuum shell • Alignment fiducials on the vacuum shell with reference to
cavity positions.
650 MHz Cryomodule Design, 21 Feb 2011 Page 13650 MHz Cryomodule Design, 21 Feb 2011 Page 13
Cryomodule requirements -- slot length
650 MHz cavities at 2 K
Warm magnets and instrumentation 11.3 meters
650 MHz Cryomodule Design, 21 Feb 2011 Page 14650 MHz Cryomodule Design, 21 Feb 2011 Page 14
Cryomodule requirements -- thermal
2 K heat load basis for pipe size*per cavity (W) 38.75
per cryomodule (W) 311.775 K heat load basis for pipe size*
per cryomodule (W) 50.4870 K heat load basis for pipe size*
per cryomodule (W) 653.46
*Heat loads for pipe sizing include uncertainty/design factor 1.5
• Cavities at nominally 2 K – 1.8 K to 2.1 K, to be determined
• One radiative thermal shield at nominally 70 K – 35 K to 80 K to be determined
• Thermal intercepts at nominally 5 K and 70 K
650 MHz Cryomodule Design, 21 Feb 2011 Page 15650 MHz Cryomodule Design, 21 Feb 2011 Page 15
Cryomodule requirements -- vessel and piping pressures
650 MHz Cryomodule Design, 21 Feb 2011 Page 16650 MHz Cryomodule Design, 21 Feb 2011 Page 16
Design considerations
• Cooling arrangement for integration into cryo system • Pipe sizes for steady-state and emergency venting • Pressure stability factors
– Liquid volume, vapor volume, liquid-vapor surface area as buffers for pressure change
• Evaporation or condensation rates with pressure change
• Updated heat load estimates• Options for handling 4.5 K (or perhaps 5 K - 8 K) thermal intercept
flow • Alignment and support stability • Thermal contraction and fixed points with closed ends
• Etc.
650 MHz Cryomodule Design, 21 Feb 2011 Page 17650 MHz Cryomodule Design, 21 Feb 2011 Page 1717
Cryomodule Pipe Sizing Criteria
• Heat transport from cavity to 2-phase pipe – 1 Watt/sq.cm. is a conservative rule for a vertical pipe (less heat
flux with horizontal lengths)
• Two phase pipe size – 5 meters/sec vapor “speed limit” over liquid – Not smaller than nozzle from helium vessel
• Gas return pipe (also serves as the support pipe in TESLA-style CM)– Pressure drop < 10% of total pressure in normal operation– Support structure considerations
• Loss of vacuum venting P < cold MAWP at cavity – Path includes nozzle from helium vessel, 2-phase pipe, may
include gas return pipe, and any external vent lines
650 MHz Cryomodule Design, 21 Feb 2011 Page 18650 MHz Cryomodule Design, 21 Feb 2011 Page 18
650 MHz Cryomodule Design, 21 Feb 2011 Page 19650 MHz Cryomodule Design, 21 Feb 2011 Page 19
Concept -- TESLA style with open pipe as support
• Use an open 300 mm dia pipe as the support structure backbone – Open to insulating vacuum – Direct connection from 2-phase pipe to vapor return
line via heat exchanger – Direct connection from 2-phase pipe to vent line – 2-phase pipe sized large for venting from one end
• Advantages – 300 mm pipe open for handling with present tooling – No end forces on 300 mm pipe or connections to it
650 MHz Cryomodule Design, 21 Feb 2011 Page 20650 MHz Cryomodule Design, 21 Feb 2011 Page 20
Stand-alone cryomodule schematic
650 MHz Cryomodule Design, 21 Feb 2011 Page 21650 MHz Cryomodule Design, 21 Feb 2011 Page 21Page 21
End Plate
Beam
650 MHz Cryomodule (Tesla Style-Stand Alone)
Power MC (8)
Vacuum vesselCold mass supports (2+1)
650 MHz Cryomodule Design, 21 Feb 2011 Page 22650 MHz Cryomodule Design, 21 Feb 2011 Page 22Page 22
Fix. support Sld. supportSld. support
300mm pipe (backbone)650 MHz cavity
Gate valveEnd plate
650 MHz layout
650 MHz Cryomodule Design, 21 Feb 2011 Page 23650 MHz Cryomodule Design, 21 Feb 2011 Page 23Page 23
-48” vacuum vessel 300 mm pipe
-80K shield, pipes:(Nom: 35mm-ID)
-Warm up-cool downpipe (nom 25mm ID)
-4K return pipe(nom 25mm ID)
-650 MC
-Thermal interceptto MC 80k & 4K
-2-Phase pipe(161mm-ID)
-80K Forward pipe
-4K Forward pipe (?)
-Thermal intercept2-phase pipe to300mm pipe (?)
X-Y section
650 MHz Cryomodule Design, 21 Feb 2011 Page 24650 MHz Cryomodule Design, 21 Feb 2011 Page 24Page 24
Heat exchanger(Location on themiddle of CM650??)
300mm pipe
Cryo-feed snout withcryogenic connections(Location on the middle of CM650??) Gate Valve
650 MHz cryomodule. End plate not shown.
Access to bayonetconnections
Access toHX and U-turnconnections
650 MHz Cryomodule Design, 21 Feb 2011 Page 25650 MHz Cryomodule Design, 21 Feb 2011 Page 25Page 25
Two He reservoirswith level sensor
Cavity needle supportsVAT needle supports (?)
Cavity string & 300mm pipe upstream side
Heat exchangerVent line with check valve2-phase pipeconnection to HX
650 MHz Cryomodule Design, 21 Feb 2011 Page 26
Cavity string & 300mm pipe downstream side
2-phase pipeThermal compensatorBlank Flange support
650 MHz Cryomodule Design, 21 Feb 2011 Page 27650 MHz Cryomodule Design, 21 Feb 2011 Page 27Page 27
Dressed cavity 650 MHz. (proposal) with MC cold-part
Ti Helium vessel OD- 450.0 mmTi 2-Phase pipe ID- 161.5 mmTi 2-Phase chimney ID- 95.5 mm
650 MHz Cryomodule Design, 21 Feb 2011 Page 28650 MHz Cryomodule Design, 21 Feb 2011 Page 28
Other concepts
• Single Spoke Resonator cryostat concept using support posts under the cavities and magnets – We may adapt that design to a 650 MHz CM
• SNS/Jlab 12 GeV upgrade style “space frame” supports – Well-developed design, works well
• BESSY/HZB CW cryomodule string rather than stand-alone cryomodules – Eliminate external transfer line (?)
• Cornell’s ERL cryomodule has some interesting features to consider although somewhat different issues
650 MHz Cryomodule Design, 21 Feb 2011 Page 29650 MHz Cryomodule Design, 21 Feb 2011 Page 29
Conclusions
• Many very good ideas and much work have already gone into cryomodule design
• Systems are different with differing requirements – Generally means adapting but not copying design
concepts
• We greatly appreciate the exchange of ideas and information which have been and will continue to be an important part of our work
650 MHz Cryomodule Design, 21 Feb 2011 Page 30
Backup slides
650 MHz Cryomodule Design, 21 Feb 2011 Page 31650 MHz Cryomodule Design, 21 Feb 2011 Page 31Page 31
Cryo Schematic -- flow through 300 mm pipe
650 MHz Cryomodule Design, 21 Feb 2011 Page 32650 MHz Cryomodule Design, 21 Feb 2011 Page 32Page 32
Empty pipe for support only or no 300 mm pipe
650 MHz Cryomodule Design, 21 Feb 2011 Page 33650 MHz Cryomodule Design, 21 Feb 2011 Page 33
SSR1 CM concept
650 MHz Cryomodule Design, 21 Feb 2011 Page 34650 MHz Cryomodule Design, 21 Feb 2011 Page 34Page 34
Vacuum vesselCold mass650 MHz Cavity
2 Support posts for each cavity:Z-fix & Z-free Cavity MC port-stabile
Heat Exchanger pipe2- phase He pipe (Ti)
650 MHz Cryomodule layout (follwing SSR concept)
650 MHz Cryomodule Design, 21 Feb 2011 Page 35650 MHz Cryomodule Design, 21 Feb 2011 Page 35Page 35
Control valvesBayonet connection
Heat exchangerVent line with check valve
650 MHz Cryomodule (following SSR concept)
Beam pipe:at the center of CM650
650 MHz Cryomodule Design, 21 Feb 2011 Page 36650 MHz Cryomodule Design, 21 Feb 2011 Page 36Page 36
Heat exchanger
Cryo feed snout
80K shieldingCold mass trayTray supports
650 MHz Cryomodule section. (SSR-style concept)
Vacuum vessel pipe-48”OD
XFEL style cavity(SNS style)
650 MHz Cryomodule Design, 21 Feb 2011 Page 37650 MHz Cryomodule Design, 21 Feb 2011 Page 37
Jlab space frame
650 MHz Cryomodule Design, 21 Feb 2011 Page 38650 MHz Cryomodule Design, 21 Feb 2011 Page 38
Jlab space frame
650 MHz Cryomodule Design, 21 Feb 2011 Page 39650 MHz Cryomodule Design, 21 Feb 2011 Page 39
Jlab space frame
650 MHz Cryomodule Design, 21 Feb 2011 Page 40650 MHz Cryomodule Design, 21 Feb 2011 Page 40
Separate liquid management in each cryomodule but no external transfer line
650 MHz Cryomodule Design, 21 Feb 2011 Page 41650 MHz Cryomodule Design, 21 Feb 2011 Page 41
ERL injector cryomodule
650 MHz Cryomodule Design, 21 Feb 2011 Page 42650 MHz Cryomodule Design, 21 Feb 2011 Page 42
ERL cryomodule features
Figure 1 from CRYOGENIC HEAT LOAD OF THE CORNELL ERL MAIN LINAC CRYOMODULE, by E. Chojnacki, E. Smith, R. Ehrlich, V. Veshcherevich and S. Chapman, Cornell University, Ithaca, NY, U.S.A.
Published in Proceedings of SRF2009, Berlin, Germany
650 MHz Cryomodule Design, 21 Feb 2011 Page 43650 MHz Cryomodule Design, 21 Feb 2011 Page 43
ERL cryomodule features
• TESLA-style support structure -- dressed cavities hang from gas return pipe (GRP), but– Titanium GRP – No invar rod, no rollers – 6 cavities per CM, 9.8 m total CM length – HOM absorbers at 40 - 100 K between cavities– GRP split with bellows at center, 4 support posts – Helium vessels pinned to GRP – Some flexibility in the input coupler – De-magnetized carbon-steel shell for magnetic shielding (this is
like TTF) – 2-phase pipe closed at each CM end, JT valve on each CM (like
BESSY design) – String rolls into vacuum vessel on rails
650 MHz Cryomodule Design, 21 Feb 2011 Page 44650 MHz Cryomodule Design, 21 Feb 2011 Page 44
RRCAT contributions
• RRCAT (Indore) is collaborating with Fermilab on 650 MHz cryomodule designs – Present focus is TESLA-style
650 MHz Cryomodule Design, 21 Feb 2011 Page 45650 MHz Cryomodule Design, 21 Feb 2011 Page 45
650 MHz Cryomodule Design, 21 Feb 2011 Page 46650 MHz Cryomodule Design, 21 Feb 2011 Page 46
SCRF Cavity supported on HGR pipe
Information required on
Magnet package Tuner details Power Coupler
Glimpses of 3-D Model (contd…)
The model incorporates a modified Cavity support system.
2K helium supply line includes a bellow in vertical configuration
650 MHz Cryomodule Design, 21 Feb 2011 Page 47650 MHz Cryomodule Design, 21 Feb 2011 Page 47
Thermal Shield with dressed Cavity
80K- Thermal shield 5K-Thermal shield is partial (Upper Part only).
Thermal shield 80K shield .
Thermal shield 5K shield is partial.
Glimpses of 3-D Model (contd…)